Lunar eclipse may be a let-down

AM Archive - Tuesday, 9 January , 2001 00:00:00

Reporter: rebacca barrett

COMPERE: The first lunar eclipse of the new millennium will happen tomorrow morning.

But don't expect anything too spectacular. The eclipse will occur just as the sun begins to rise, so most of the colours will be washed out.

But it will still be visible from Australia, and the further west you go the better the view will be.

Dr David Malin, a photographer and astronomer at the Anglo-Australian Observatory, is speaking to Rebecca Barrett:

DAVID MALIN: They'll see the moon begin to fade. Actually it starts before twilight, but it never gets really dark. What happens of course is that the shadow of the Earth drifts across the Moon. But it's a very blurry shadow because the Earth and Moon are a good way apart. And the Moon begins to fade away.

In a very good lunar eclipses the Moon turns a brilliant orange-yellow colour and it looks very beautiful, like a great peach hanging in the sky. You won't see that on this occasion.

REBECCA BARRETT: So the Moon won't disappear completely?

DAVID MALIN: No, it never does. And it never does because some of the e the Earth's shadow is not perfect, and the light from the Sun which reaches the Moon travels through the Earth's atmosphere, and that's what gives the Moon its reddish colour.

If you were standing on the Moon and you saw this happen, you'd see a brilliant ring of reddish-orange light, which is the Earth's atmosphere scattering the light from the Sun, which never arrives directly.

REBECCA BARRETT: When was the last lunar eclipse?

DAVID MALIN: The last one. Well, I can't remember exactly when it was, but I remember one in the middle of last year which was an absolute beauty. It happened around midnight, and the Moon looked like a gorgeous, oh, like an orange standing up high in the sky. I've never seen anything quite like it. It was a perfect lunar eclipse.

They don't happen too often, although we do get quite a few lunar eclipses. There'll be two more this year, for example. You get two or three a year of various qualities, and the quality depends on how precisely the Earth and the Sun and the Moon are lined up. And in July the alignment was perfect.

REBECCA BARRETT: Is there any scientific significance in a lunar eclipse?

DAVID MALIN: Not really. They're just beautiful spectacles. There's a lot of history attached to them, of course. People tried to work out what was going on and why they happen. It doesn't take long for you to realise that lunar eclipses always occur at full Moon, and solar eclipses always occur at new Moon.

And if you think about that long enough you realise that it's due to the alignment of the three objects in the sky e the Sun and the Earth and the Moon e in various orientations. So there's a kind of a lot of historical interest in working out what makes an eclipse work. But these days, apart from the solar eclipse, when the Moon goes in front of the Sun, there is no real scientific interest.

REBECCA BARRETT: So, for those planning to go out and have a look at the lunar eclipse tomorrow morning, is your advice perhaps not to bother?

DAVID MALIN: Oh, if you love watching celestial mechanics at work, you love watching the interplay between the Earth and the Sun and the Moon, then you should be there and do that because it's a lovely thing to do.